The following abbreviations that appear below are defined as follows:    2G Second Generation    3G Third Generation    3GPP Third Generation Partnership Project for UMTS    3GPP2 Third Generation Partnership Project for CDMA 2000    AMC Adaptive Modulation and Coding Scheme    BTS Base Transceiver Station    CDMA Code Division Multiple Access    CDR Charge Data Record    DL Down Link    DSRP Dynamic Source Routing Protocol    EGPRS Enhanced General Packet Radio Services    GGSN Gateway GPRS Support Node    GPRS General Packet Radio Service    GSM Global System for Mobile Communications    HSDPA High Speed Downlink Packet Access    HS-PDSCH High Speed Physical Downlink Shared Channel    IMS IP Multimedia Sub-System    IP Internet Protocol    IPSec Internet Protocol Security    MAC Medium Access Control    MAC-hs Medium Access Control—High Speed    MIMO Multiple Input Multiple Output    Node B UMTS Base Transceiver Station Node    OFDMA Orthogonal Frequency Division Multiple Access    OTA Over the Air    PAN Personal Access Network    PDCP Packet Data Convergence Protocol    PDP Packet Data Protocol    PS Packet Switched    PUG PAN User Group    QAM Quadrature Amplitude Modulation    RAB Radio Access Bearer    RDR Route Discovery Request    RLC Radio Link Control    RNC Radio Network Control unit    RP Routing Protocol    Rx Receive    SGSN Serving GPRS Support Node    SIP Session Initiation Protocol    TCP Transaction Control Protocol    TDMA Time Division Multiple Access    Tx Transmit    UE User Equipment    UL Uplink    UMTS Universal Mobile Telecommunication System    UWB Ultra Wide Band    WCDMA Wideband Code Division Multiple Access
In current 2G/3G access system solutions such as GSM, EGPRS, UMTS and CDMA each mobile device communicates with the network using protocols and signaling as specified in the various standards such as 3GPP and 3GPP2. The data rates that can be achieved are limited to the specification in the standards and by real world radio environment and network conditions. The future evolution of access technologies use various known methods and techniques to achieve higher gains (e.g., Advanced modulation and coding schemes, MIMO concepts, diversity techniques, antenna beam-forming, 2-way/4-way Rx equalizers and advanced receivers). All of these concepts and techniques may provide gain, but at a certain cost. In some cases the gains cannot be practically realized, for example, it is anticipated that 16 QAM AMC will be used only about 5% of the time in a real world macro environment for HSDPA. Further, although standards specify the use of 15 HS-PDSCH codes, the probability of mobile devices using more than five codes is very low in a macro cell environment. Further, for a MIMO realization the addition of multiple antennas at the mobile device presents significant complexity and other challenges. Also, mobile manufacturers may not implement some of these concepts due at least to commercial reasons. The end result is that even though technology evolves, the real-world usability of the technology will be limited.